3 Introduction Oracle Linux is fully compatible both source and binary with Red Hat Enterprise Linux. Partners testing and certifying their applications on Oracle Linux will, at most, simply install their application on Oracle Linux and verify the information described in this article. When using the Red Hat compatible kernel, Oracle Linux 5 is also fully kabi compatible with Red Hat Enterprise Linux. This article describes the key points that ISVs should consider when installing and certifying their products on Oracle Linux 5. 1

4 Comparing Oracle Linux 5 and Red Hat Enterprise Linux (RHEL) 5 Applications that run on RHEL will run on Oracle Linux. Trademarks and logos have been removed from a small number of the packages. These are non-functional text or graphics changes that in no way affect any program code, and they do not generate any compatibility issues. Oracle has added its own text file, /etc/, so support teams can easily identify that they obtained the code from Oracle. The Edison Group ran independent tests to validate Oracle s claim of compatibility: Read their report, Oracle Linux: True Enterprise-Quality Linux Support (see page 15). Oracle s simple text changes that an installer program might encounter are listed in the following sections. Checking the /etc/ File RHEL provides a text file called /etc/, which contains a one-line string identifying the specific distribution release. This file is part of the package. Oracle Linux 5 also contains a text file called /etc/, which is installed by a package called. The following tables show the data that is present on the initial release of media for each of the releases of Oracle Linux. As of Oracle Linux 5.3, Oracle retains the Red Hat content within the file. Also shown is the file /etc/, which contains Oracle content. RHEL 5 ORACLE LINUX 5-5Server (Tikanga) Enterprise Linux Enterprise Linux Server release 5 (Carthage) RHEL 5 UPDATE 1 ORACLE LINUX 5 UPDATE 1-5Server (Tikanga) Enterprise Linux Enterprise Linux Server release 5.1 (Carthage) 2

12 RHEL 5 UPDATE 11 ORACLE LINUX 5 UPDATE 11-5Server rpm qa grep rpm q provides config() = 6: = 6: Checking the Version of the Distribution An application may check for the version of the distribution. In this case, RHEL 5 returns 5Server, whereas Oracle Linux 5 returns 5. RHEL 5: rpm q qf %{version}\n f /etc/ 5Server Oracle Linux 5: rpm q qf %{version}\n f /etc/ 5 Applications using the %{version} rpm check simply need to check for 5, not 5Server. The preceding items are the only major differences between RHEL 5 and Oracle Linux 5 that might impact installation and certification. If your application installer depends on any of the checks described above, you now have all the information needed to make the minimal changes required to transparently run on both Oracle Linux 5 and RHEL 5. Unbreakable Enterprise Kernel In September of 2010, Oracle introduced the Unbreakable Enterprise Kernel for Oracle Linux. You can read more about Unbreakable Enterprise Kernel here. Beginning with Oracle Linux 5.5, 10

13 customers have a choice when it comes to the kernel: strict compatibility with the Red Hat kernel or a kernel optimized and recommended by Oracle for stability and performance. Unbreakable Enterprise Kernel, Compatibility, and Third-Party Software One of the main advantages of Unbreakable Enterprise Kernel is that it runs directly on Oracle Linux 5. This means that you can benefit from significant performance improvements and new features without the need to re-install the entire operating system. Because the operating system itself is not replaced, third-party applications will run unchanged. The Linux operating system is a modular system in which the kernel interacts with the hardware and controls and schedules access to resources on behalf of applications. Applications run in what s called user space and call only a stable set of system libraries to ask for kernel services. Figure 1 is a simplified diagram of the Linux operating system. Installing Unbreakable Enterprise Kernel changes only the box labeled Kernel. 11

14 Figure 1. Linux Operating System As you can see, installing a kernel does not change system libraries such as glibc, the interface that nearly all applications, including Oracle Database, use. The glibc version is 2.5 before and after you install Unbreakable Enterprise kernel on Oracle Linux 5.5. The sysctl infrastructure to control kernel settings is also unchanged when you install Unbreakable Enterprise Kernel. In contrast, device drivers and other kernel modules are tightly coupled with the kernel and will usually need to be recompiled when a new kernel is introduced. 12

15 For ISVs That Also Check the Linux Kernel Version As of Oracle Linux 5 Update 5, there are three kernels options: Unbreakable Enterprise Kernel ( x.y.z or newer) Red Hat compatible kernel ( x.y.z.el5) Red Hat compatible kernel with Oracle bug fixes ( x.y.z.n.m.el5) As of Oracle Linux 5 Update 6, Unbreakable Enterprise Kernel is installed and booted by default. The Red Hat compatible kernel is also installed, and you may configure the operating system to boot with this kernel instead. The Unbreakable Enterprise Kernel is provided by the kernel-uek package, whereas the Red Hat compatible kernel is provided by the kernel package. ~] rpm qa grep kernel kernel-uek-firmware el5uek kernel-uek el5 kernel el5 Staring from Oracle Linux 5 Update 7,Unbreakable Enterprise Kernel is available on x86 and x86-64 platform. To determine whether Unbreakable Enterprise Kernel is installed and running, look for a kernel release version of or newer using the uname r command: uname r el5 Also, make sure that the kernel package installed is called kernel-uek. rpm qa grep kernel-uek kernel-uek el5uek kernel-uek-firmware el5uek For Oracle Linux 5 through Update 5, the default installed kernel is the Red Hat compatible kernel, kernel x.y.z.el5. When custom kernels are built for resolving customer issues, any other sort of numbering might be used and should not necessarily be relied upon. However, a standard RHN release kernel follows the format above. The Oracle Linux 5 Red Hat compatible kernel with Oracle bug fixes keeps the exact same kernel versions and adds more digits at the end to identify potential fixes incorporated. As always, these fixes are applied only if they are critical fixes not yet applied by Red Hat, and Oracle considers the fixes to be important for customer scenarios. Oracle always provides all fixes to Red Hat and the community in the hope that they will be incorporated in a future release. Oracle does not have more than a few patches applied at any given time. If your product includes a kernel module, please contact us, 13

16 For applications that ship binary kernel modules or check a specific kernel release, uname r or rpm q kernel returns additional digits in the kernel version (as shown in the following tables) only if the Red Hat compatible kernel with Oracle patches is installed. In this case, Oracle appends additional digits to the end of the release number. Patch files for Oracle-provided fixes are available at The following table shows the expected output from uname r on Red Hat Enterprise Linux 5, Oracle Linux 5 running the Red Hat compatible kernel with Oracle bug fixes and Unbreakable Enterprise Kernel. MINOR RELEASE RHEL 5 KERNEL ORACLE LINUX 5 RED HAT COMPATIBLE KERNEL WITH ORACLE BUG FIXES ORACLE LINUX 5 UNBREAKABLE ENTERPRISE KERNEL Update el el5 Not Available Update el el5 Not Available Update el el5 Not Available Update el el5 Not Available Update el el el5 Update el el el5uek Update el el el5uek Update el el el5uek Update el el el5uek Update el el el5uek Update el el el5uek Full, Verified kabi Compliance Oracle Linux 5 with a Red Hat compatible kernel is fully kabi compatible with RHEL 5. Scripts are run to double-check whether any patches that were to be applied would have a chance of breaking kabi. Any comparison between any kernel of Oracle Linux 5 and RHEL 5 shows absolutely no difference in kabi. Kernel modules built for any RHEL 5 kernel (since the original release) will also load on any Red Hat compatible kernel released for Oracle Linux 5. 14

17 Compatibility The preceding information compares Oracle Linux 5 and RHEL 5 and highlights areas of importance to application vendors from a testing and certification point of view. If your application relies on any of the examples above, you now have all the information needed about any changes that are required to run your application on Oracle Linux. If your application does not rely on any of the examples above, it will run transparently, and Oracle is confident that re-certification is not necessary. Downloading Source Code and Binaries Oracle Linux source code is available for free for download at The binaries are freely downloadable at Oracle Linux 5 allows for free re-distribution of both source and binaries. Conclusion Oracle Linux is fully compatible both source and binary with with Red Hat Enterprise Linux. This article described key points that ISVs should consider when installing and certifying their products on Oracle Linux 5. For More Information Visit the Oracle Linux Knowledge Zone on the Oracle PartnerNetwork to learn how to accelerate market opportunity and lower the cost of providing Linux solutions and support to users. For more information about becoming an Oracle partner, visit the Oracle PartnerNetwork. For information on the Oracle Unbreakable Linux support program, visit oracle.com/linux. For ISV contact, 15

18 Certification with Oracle Linux 5 October 2014 Authors: Keshav Sharma, Michele Resta and Ryo Kurechi Oracle Corporation World Headquarters 500 Oracle Parkway Redwood Shores, CA U.S.A. Copyright 2014, Oracle and/or its affiliates. All rights reserved. This document is provided for information purposes only, and the contents hereof are subject to change without notice. This document is not warranted to be error-free, nor subject to any other warranties or conditions, whether expressed orally or implied in law, including implied warranties and conditions of merchantability or fitness for a particular purpose. We specifically disclaim any liability with respect to this document, and no contractual obligations are formed either directly or indirectly by this document. This document may not be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without our prior written permission. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Worldwide Inquiries: Phone: Fax: oracle.com Intel and Intel Xeon are trademarks or registered trademarks of Intel Corporation. All SPARC trademarks are used under license and are trademarks or registered trademarks of SPARC International, Inc. AMD, Opteron, the AMD logo, and the AMD Opteron logo are trademarks or registered trademarks of Advanced Micro Devices. UNIX is a registered trademark of The Open Group. 0113

An Oracle White Paper July 2013 Introducing the Oracle Home User Introduction Starting with Oracle Database 12c Release 1 (12.1), Oracle Database on Microsoft Windows supports the use of an Oracle Home

An Oracle White Paper March 2013 Oracle s Single Server Solution for VDI Introduction The concept of running corporate desktops in virtual machines hosted on servers is a compelling proposition. In contrast

An Oracle White Paper May 2011 Distributed Development Using Oracle Secure Global Desktop Introduction One of the biggest challenges software development organizations face today is how to provide software

An Oracle Communications White Paper December 2014 Serialized Asset Lifecycle Management and Property Accountability Disclaimer The following is intended to outline our general product direction. It is

An Oracle White Paper November 2010 Oracle Business Intelligence Standard Edition One 11g Introduction Oracle Business Intelligence Standard Edition One is a complete, integrated BI system designed for

General Overview What is Oracle s Virtual Compute Appliance? Oracle s Virtual Compute Appliance is an integrated, wire once, software-defined infrastructure system designed for rapid deployment of both

An Oracle White Paper February 2013 Integration with Oracle Fusion Financials Cloud Service Executive Overview Cloud computing is a vision that is increasingly turning to reality for many companies. Enterprises,

An Oracle White Paper February 2014 Oracle Data Integrator 12c Introduction Oracle Data Integrator (ODI) 12c is built on several components all working together around a centralized metadata repository.

March 2014 Oracle Business Intelligence Discoverer Statement of Direction Oracle Statement of Direction Oracle Business Intelligence Discoverer Disclaimer This document in any form, software or printed

User Experience Direct (UX Direct) FAQ: How to create Effective Messages Disclaimer The following is intended to outline our general product direction. It is intended for information purposes only, and

THE NEW BUSINESS OF BUSINESS LEADERS Hiring and Onboarding 2 INTRODUCTION Unlocking the potential of your talent is key to the success of your organization. Leading businesses actively dedicate resources

An Oracle White Paper October 2011 BI Publisher 11g Scheduling & Apache ActiveMQ as JMS Provider Disclaimer The following is intended to outline our general product direction. It is intended for information

Oracle Primavera Gateway Disclaimer The following is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is

SIX QUESTIONS TO ASK ANY VENDOR BEFORE SIGNING A SaaS E-COMMERCE CONTRACT When evaluating software-as-aservice, particularly e-commerce SaaS solutions, companies often focus on comparing product features

ORACLE VM MANAGEMENT PACK Effective use of virtualization promises to deliver significant cost savings and operational efficiencies. However, it does pose some management challenges that need to be addressed

A Framework for Implementing World-Class Talent Management The highest performing businesses are re-focusing on talent management The highest performing businesses are re-focusing on talent management.

SELF SERVICE PROCUREMENT Oracle Fusion Self Service Procurement streamlines the purchase requisitioning process using a consumer centric approach and helps control the employee spending by enforcing the

An Oracle White Paper February 2010 Rapid Bottleneck Identification - A Better Way to do Load Testing Introduction You re ready to launch a critical Web application. Ensuring good application performance

October 2013 A New Standard for Excellence Transforming Education and Research with Oracle Innovation Disclaimer The following is intended to outline our general product direction. It is intended for information

Minutes on Modern Finance Midsize Edition Roadmap to a Successful Cloud Implementation 5 Steps to Consider for Ensuring a Successful Implementation If you are a growing midsize organization, chances are

Oracle Database Backup Service Secure Backup in the Oracle Cloud Today s organizations are increasingly adopting cloud-based IT solutions and migrating on-premises workloads to public clouds. The motivation

October 2015 Oracle Application Express Statement of Direction Disclaimer This document in any form, software or printed matter, contains proprietary information that is the exclusive property of Oracle.

An Oracle White Paper May 2013 Creating Custom PDF Reports with Oracle Application Express and the APEX Listener Disclaimer The following is intended to outline our general product direction. It is intended

An Oracle White Paper August 2010 Oracle Database Auditing: Performance Guidelines Introduction Database auditing has become increasingly important as threats to applications become more sophisticated.

PRODUCT HUB Centralize product data across heterogeneous systems to create a blended product master record that is clean, standardized, accurate, and current. Harmonize it across business processes and

An Oracle White Paper Dec 2013 Oracle Access Management Security Token Service Disclaimer The following is intended to outline our general product direction. It is intended for information purposes only,

April 2014 Oracle Higher Education Investment Executive Brief Disclaimer The following is intended to outline our general product direction. It is intended for information purposes only, and may not be

Oracle Hyperion Financial Close Management Oracle Hyperion Financial Close Management is built for centralized, webbased management of period-end close activities across the extended financial close cycle.

Oracle s Primavera Prime Capital Plan Management The nature of capital projects necessitate planning for not only infrastructure needs, but for the operational and regulatory requirements of the infrastructure

An Oracle White Paper May 2011 BETTER INSIGHTS AND ALIGNMENT WITH BUSINESS INTELLIGENCE AND SCORECARDS 1 Introduction Business Intelligence systems have been helping organizations improve performance by

Simplify IT and Reduce TCO: Oracle s End-to-End, Integrated Infrastructure for SAP Data Centers Over time, IT infrastructures have become increasingly complex and costly to manage and operate. Oracle s

An Oracle White Paper May 2010 SQL Profiles: Technical Overview SQL Profiles: Technical Overview What is a SQL profile? A SQL profile is a set of auxiliary information specific to a SQL statement. Conceptually,

An Oracle White Paper August 2010 Oracle OpenSSO Fedlet Disclaimer The following is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated

An Oracle Best Practice Guide April 2012 Best Practices for Knowledgebase and Search Effectiveness Introduction Ensuring that your knowledgebase is properly optimized to help customers find what they need